6 BULLETIN 565, U. S. DEPARTMENT OF AGRICULTURE. 
and the other two eggs are brought forward by a dexterous move- 
ment of hand and palm, held before the light, and graded. The 
ability to shift two eggs in each hand makes for more rapid work 
and ma} T be acquired by practicing with china eggs. A good deal of 
experience is required to shift eggs safety and quickly. 
During candling the egg should come in contact with the fingers 
as little as possible, so that small blemishes such as mold spots will 
not be hidden from view. It is advisable not to hold more than two 
eggs in each hand during candling because of the added chance of 
breaking the eggs and confusing the grades. 
Until the beginner has had some experience it will be advisable 
for him frequently to check the decision reached by candling with 
the appearance of the egg when broken into a saucer or other con- 
venient receptacle. 
WHAT TO LOOK FOR IN CANDLING AN EGG. 
The relation of the shell, air space, white, and yolk to grading by 
candling will be discussed separately before taking up the considera- 
tion of the different kinds of eggs. After the beginner has become 
acquainted with the different factors which influence the grading of 
an egg. it is a comparatively simple matter for him to recognize the 
predominating characteristics of each egg and to place the egg in its 
proper grade. 
THE SHELL. 
It is possible to grade eggs by inspection through the shell because 
of the partial transparency of the shell when held before a light in 
a dark room. The egg contents can be seen much more plainly 
through a white shell than through a brown one. The light shining 
through a white egg. on candling, is yellow, with a slightly pinkish 
tinge; that from a brown egg is much pinker; and that from a dark 
brown egg is almost red. In each instance, the color deepens in the 
region of the yolk. The contrast between the white and the yolk 
is much greater in white than in brown eggs. The appearance before 
the candle of a fresh white and a fresh brown egg is shown in 
Plates I and II. The beginner should study eggs with white shells 
first and postpone the study of eggs with brown shells until he has 
had some experience. Likewise he should begin with clean eggs, for 
the reason that dirt or stains on the shell may cast a shadow on the 
contents and thus render accurate candling difficult. Candling of 
eggs with mottled, warty, or uneven shells should also be deferred. 
The colored sketches of the different kinds of eggs shown in this 
bulletin were made, with few exceptions, from eggs with white shells, 
and were selected to show as much of the interior as possible. The 
descriptions in most instances will apply to white eggs. These facts 
